const gulp = require('gulp'),
      htmlmin = require('gulp-htmlmin'),
      cleanCss = require('gulp-clean-css'),
      babel = require('gulp-babel'),
      uglify = require('gulp-uglify'),
      del = require('del'),
      connect = require('gulp-connect'),
      sass = require('gulp-sass')


const paths = {
  html: {
    src: 'src/**/*.html',
    dest: 'dist'
  },
  css: {
    src: 'src/css/**/*scss',
    dest: 'dist/css'
  },
  js: {
    src: 'src/js/**/*.js',
    dest: 'dist/js'
  },
  img: {
    src: 'src/img/**',
    dest: 'dist/img'
  },
  libs: {
    src: 'src/libs/**',
    dest: 'dist/libs'
  },
  ico: {
    src: 'src/**',
    dest: 'dist'
  }
}

const delDist = () => del('dist')

const html = () => {
  return gulp.src(paths.html.src)
    .pipe(htmlmin({
      removeComments: true, // 清除HTML注释
      collapseWhitespace: true, // 压缩HTML
      collapseBooleanAttributes: true, // 省略布尔属性的值 <input checked="true"/> ==> <input checked />
      removeEmptyAttributes: true, // 删除所有空格作属性值 <input id="" /> ==> <input />
      removeScriptTypeAttributes: false, // 删除<script>的type="text/javascript"
      removeStyleLinkTypeAttributes: true, // 删除<style>和<link>的type="text/css"
      minifyJS: true, // 压缩页面JS
      minifyCSS: true // 压缩页面CSS 
    }))
    .pipe(gulp.dest(paths.html.dest))
    .pipe(connect.reload())
}

const css = () => {
  return gulp.src(paths.css.src)
    .pipe(sass())
    .pipe(cleanCss())
    .pipe(gulp.dest(paths.css.dest))
    .pipe(connect.reload())
}

const js = () => {
  return gulp.src(paths.js.src)
    .pipe(babel({
      presets: ['@babel/env']
    }))
    .pipe(uglify())
    .pipe(gulp.dest(paths.js.dest))
    .pipe(connect.reload())
}

const img = () => gulp.src(paths.img.src).pipe(gulp.dest(paths.img.dest))

const libs = () => gulp.src(paths.libs.src).pipe(gulp.dest(paths.libs.dest))

const ico = () => gulp.src(paths.ico.src).pipe(gulp.dest(paths.ico.dest))

const server = () => {
  return connect.server({
    root: 'dist',
    port: 88,
    livereload: true
  })
}

const watch = () => {
  gulp.watch(paths.html.src, html)
  gulp.watch(paths.css.src, css)
  gulp.watch(paths.js.src, js)
}

module.exports.default = gulp.series(delDist, gulp.parallel(html, js, css, img, libs, server, ico,watch))
